BlackBerrys are slowly but surely being turned into satnav devices. T-Mobile announced this week that a satnav application would be available on BlackBerry; now Garmin has announced that its new Mobile 10 application would be available on selected BlackBerrys. The software is also available for Bluetooth-enabled devices that range from notebooks to PDAs.

Garmin Mobile is the first off-board mobile navigation system to visually depict and constantly update the user’s position on a moving map. It’s “off-board” because all the mapping data is stored on Garmin’s servers, not on the device, be it BlackBerry or other.

Customers wishing to use the software will have to pair their device with either ra GPS 10x or GPS 20SM. The 10x is a portable GPS sensor that transmits information via Bluetooth, while the 20SM is a portable phone cradle with built-in GPS receiver.

Garmin Mobile gives users voice directions to their destination, and is able to offer real-time re-calculated routing if the user goes off-course.

The BlackBerry edition gives real-time traffic service information, as well as fuel and weather information for North America. It will be available on a yearly contract in that territory, while Garmin Mobile 10 itself is available for other devices for just under $200.